A widespread farming catastrophe could hit Africa if global temperatures rose by four degrees Celsius or more, according to a study that calls for urgent planning for a much warmer future and investment in technology to avert disaster.

In most of southern Africa the growing season could shrink by as much as a fifth, according to scientists at the International Livestock Research Institute (ILRI) in Kenya, who carried out simulation studies based on existing climate change models.

ADVERTISEMENT

The 'four degrees plus' scenario is increasingly being contemplated as negotiations, which began again in Cancún, Mexico, today (29 November—10 December), have stalled on measures aimed at limiting the global temperature rise to two degrees.

Drastic changes to farming will be needed under such a scenario, said Carlos Seré, director-general of ILRI.

"The general feeling is that the world is not going to move quickly enough on [confining global warming to] two degrees," he told SciDev.Net: "We are not getting traction.

"The common thinking has been that there will be enough variability in farming today to allow us to cope, but the reality is that in a four degree world the range of options is very narrow."

According to the models, the growing season may increase modestly in eastern Africa. But cropping seasons are likely to decline more quickly everywhere in the region except central Africa.

Much of southern Africa's rain-fed agriculture could fail every other season by the 2090s, says the study.